The present invention concerns the automatic control of the position of the working tool of an earth working machine and, according to the preferred embodiment, the position of the blade of the motor grader. More specifically, the present invention concerns the control of the transverse slope of the working tool or blade of an earth working machine. The preferred embodiment of the invention relates to the slope control of the blade of a motor grader although it is recognized that other types of machines may be controlled by the present invention.
In view of today's highway requirements, particularly high speed travel over modern highways, the demand for greater accuracy in preparing road beds for surfacing is substantial. At the same time, the grading operation must be accomplished quickly and efficiently in order to cope with the long distances over which our today's modern highways are to stretch. The present invention provides for quick and efficient operation of a grading machine by providing automatic control and provides for a highly accurate grading operation by providing refinements in the slope control system of the automatic control.